This patch fixes Vampires being able to stand on altars.
(It says in the fixes32.0 "don't let vampires step on altars")

I hope this fix helps. Let me know what you think!
Chris Becker (topher@csh.rit.edu)

More bug fixes and patches can be found at 
http://www.csh.rit.edu/~topher/nethack

diff -aur ..\original\nethack-3.4.3\src\mon.c nethack-3.4.3\src\mon.c
--- ..\original\nethack-3.4.3\src\mon.c	Sun Dec 07 16:39:14 2003
+++ nethack-3.4.3\src\mon.c	Fri Jan 02 19:34:36 2004
@@ -1095,7 +1095,12 @@
 		}
 
 		info[cnt] = 0;
-		if ((checkobj || Displaced) && onscary(dispx, dispy, mon)) {
+		/* doesn't seem to be a need for the first statement below
+		 * maybe at some point for a speed up but it skips altars
+		 * which are scary but are not objects and can be scary without
+		 * displacement - Chris Becker (topher@csh.rit.edu)
+		 */
+		if (/*(checkobj || Displaced) &&*/ onscary(dispx, dispy, mon)) {
 		    if(!(flag & ALLOW_SSM)) continue;
 		    info[cnt] |= ALLOW_SSM;
 		}